A Novel Assessment Tool for Alzheimer's and Frontotemporal Dementias Jeanyung Chey 1,2, Hyun Song 2, Jungsuh Suk 1, & Minue J. Kim 3 The Proportional Reasoning Test: 1 Department of Psychology, Seoul National University, Seoul, Republic of Korea 2 Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Republic of Korea 3 Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH Dementia evaluation in elderly population involves assessment of higher cognitive functions, such as conceptualization, which involves intact functioning of the prefrontal cortex. Popular executive function tests, such as the Wisconsin Card Sorting Test, require the utilization of conceptualization learned from formal education. However, these tests may not correctly reflect functioning of the prefrontal region in people with limited education by underestimating its function in these populations. As an alternative to these tests, the Proportional Reasoning Test (PRT), an equivalence matching test based on numerical and quantitative conceptualization, has been developed. Previous studies using this new test supported its clinical validity for patients with two types of dementias, Alzheimer's disease (AD) and fronto-temporal dementia (FTD) in elderly population with low education. Specifically, demented patients performed worse than chance, whereas normal elderly subjects performed well-above chance level regardless of their education level. In the present study, we examined its neural correlate, as a next step toward validating the PRT as a neuropsychological tool, using functional magnetic resonance imaging (fMRI) INTRODUCTION METHODS The PRT is a neuropsychological tool assessing the prefrontal region in elderly people with limited education, and possibly a test of the fronto- parietal network that is important in higher-cognitive functions. Considering the fact that global aging involves many elderly populations with limited or no education, this test could be useful in assessing dementia in societies where many elderly people received only minimal education. CONCLUSIONS  Procedure  Subjects 25 healthy elderly women with various educational backgrounds (age 62.9±4.0 yr, education level 7.4±6.3 yr, Right-handed) Screening fMRI Experiment Health Screening Exclusion Criteria Geriatric Depression Scale (GDS) Korean Dementia Rating Scale (KDRS-2) Literacy Safety screening for MRI scan Handedness Practice (12 easy trials only for practice) Event-related fMRI 2 stimuli sets (Discrete set and Continuous set) with 2 conditions respectively (e.g., Exp and Ctl) Pseudorandom 8 runs (128 trials for each run, 32 trials per condition)  fMRI Experiment Proportional Reasoning Test Event-related Figure 1. Examples of the Proportional Reasoning Test (PRT) and fMRI experiment In each trial, a correct answer, a target and, a distractor were presented side by side. Participants had to identify the number or amount of the target and reason the correct answer which was in proportion to the number or the amount of the target, while controlling concrete thinking (i.e., a distractor) to correctly choose their response. During fMRI experiment, subjects were instructed to complete the PRT and a control task, a simple matching task requiring matching identical figures, presented in pseudorandom order. These tasks were followed by a fixation cross which served as the baseline at the end of the run.  Data Acquisition 3.0 Tesla MRI scanner (Magnetom TrioTim, Siemens, Erlangen, Germany) during the Proportional Reasoning Task  Data Analysis Behavioral Data: PASW Statistics 18 Neuroimaging Data: SPM8 1 st level analysis: General Linear Model (PRT vs. Control Task) 2 nd level analysis: One sample t test RESULTS  fMRI results  Behavior results All participants performed well on the PRT regardless of the level of formal education (i.e., mean percent accuracy 92.1%, range ) Brodmann area # of voxels T max Talairach coordinates XYZ L Angular Gyrus**BA R Supramarginal Gyrus**BA L Cingulate Gyrus**BA R Superior Frontal Gyrus*BA Note. voxels above threshold (p <.01 uncorrected, extent threshold = 50 voxels) were reported. In each area, the maximum t value and its MNI coordinates were converted to Talairach coordinates using an algorithm by Mattew Brett. Labels indicate the nearest gray matter from coordinates within 2 mm. * Significant at p < (uncorrected), extent threshold = 5 voxels, ** Significant at p <.05 (FDR corrected) Table 1. Regions showing increased activation during the PRT compared to control matching task Figure 2. PRT related activation maps Activation was significantly greater in the frontal and parietal cortices during the PRT than that of control task. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (No ) ACKNOWLEDGEMENT